Method of making high solids, high protein dairy-based food

ABSTRACT

The present invention provides a process for producing a high solids/high protein dairy product wherein an MPC is first mixed with molten fat to produce a mixture of protein particles coated in fat and the mixture hydrated, acidified and heated under low shear to produce a dairy product, preferably a cheese or cheese-like product having a protein to water ratio of between 0.6 and 3.0.

The present application is the U.S. National Phase of PCT/NZ02/000279,filed Dec. 17, 2002, and claims priority under 35 U.S.C. §119 to NewZealand Patent Application No. 516210, filed Dec. 17, 2001.

FIELD OF THE INVENTION

The present invention relates to the manufacture of high-solids,high-protein, dairy-based food products and in particular to themanufacture of cheese or cheese-like products.

The invention has been developed primarily for use in the development ofhard cheeses or hard cheese-like products and will be describedhereinafter with reference primarily to this application. However, itwill be appreciated that the invention is not limited to this particularfield of use.

BACKGROUND OF THE INVENTION

In most traditional cheese making processes, the whey proteins of milk,although highly nutritious, are removed from cheese curd in a wheydrainage step. More recent advances have led to the development ofprocesses for making cheese or cheese-like products that have eliminatedthe whey drainage step thereby improving both cheese yield andnutrition.

Patent Application WO 00/27214 (Blazey et al) is an example of a processfor producing cheese that has eliminated the whey drainage step. Thisdocument discloses a method of making cheese in which pH adjusted,concentrated or reconstituted milk is ultra and diafiltered to produce aretentate. The retentate is then supplement with a protein concentrateor isolate; and the resulting mixture is heated to produce a smoothconsistency. No enzymes, enzyme cultures, or micro-organisms need beemployed by the process.

Other recent developments involve the manufacture of cheese from a milkprotein concentrate powder. Such methods have the advantage that cheesemanufacture can be uncoupled from supply. That is, because the milkconcentrate powder, when compared to fresh milk, can be stored for asignificantly longer period without significant degradation (in terms ofthe ability to be converted to cheese-type products) cheese can beproduced on demand, rather than being linked directly to milk supply.Manufacture of cheese from milk protein concentrate powder can alsoprovide cost benefits in transport. Such benefits result from having aproduct that is of lower weight and volume than milk and that can beused to manufacture cheese.

U.S. Pat. No. 6,183,804 (Moran et al) discloses a two stage process forproducing a process cheese-type product. The first stage of the processinvolves producing a powder milk protein concentrate by ultrafiltrationto produce a retentate and then spray drying the retentate. The secondstage of the process involves hydrating the powdered milk proteinconcentrate by mixing the powered milk protein concentrate with waterand adjusting the pH of the hydrated milk protein concentrate to between4.8 and 5.5. Optionally fat is added to the mixture. The mixture is thenheated and subjected to shear to form fresh cheese. Flavour additivesand emulsifiers are blended with the fresh cheese during a furtherheating step for a time sufficient to obtain a homogeneous processcheese-type product. Once again no enzymes, enzyme cultures, ormicro-organisms are employed and there is no formation or separation ofcurds and whey. U.S. Pat. No. 6,183,804 also discloses that cream may beused to hydrate the powdered milk protein concentrate.

U.S. Pat. No. 6,242,016 (Mehnert et al) discloses the manufacture ofgrated Parmesan cheese using an ultrafiltered retentate. The retentateis then fermented followed by the addition of a milk clotting enzyme.The fermented retentate is then subjected to an evaporation step to forma Parmesan cheese with a moisture content of 18 to 24%.

U.S. Pat. No. 4,444,800 (Bixby et al) discloses the manufacture ofimitation cheese products of up to 70% total solids (30% moisture). Ituses rennet casein and emulsifying salts.

U.S. Pat. No. 5,165,945 (Yee et al) also discloses the manufacture ofhigh solids content cheese. The cheese is made by subjecting milk toultra and diafiltration, adding a milk clotting enzyme and heating for asufficient time to coagulate the retentate and followed by the removalof water. Again this is a direct from milk process. The inventors inU.S. Pat. No. 5,165,945 note that excessive solids result in an oily andbroken down texture. The document discloses the process of the inventionis capable of producing cheese having solids content from 40 to aboveabout 70% by weight. The clotting enzyme is essential to provide suchhigh solids content according to this process. It is generallyconsidered in the art (for example Fitzpatrick J J et al, Practicalconsiderations for reconstituting dairy powders to high solids contentin a stirred-tank, Milchwissenschaft 56(9) 2000, pages 512-516) that ahigh-solids, high-protein recombining process would result in thedevelopment of extremely high viscosities during hydration. It is alsogenerally considered that rapid formation of the protein matrix wouldprovide inadequate time for fat dispersion and, simultaneously, fatdestabilization would occur as the protein matrix tightened.

It is an object of the present invention to provide a flexible and rapidprocess for the manufacture of a high-solids (low moisture),high-protein, dairy-based food product such as a hard cheese block,cheese “crumble”, grated/milled hard cheese or dairy-based condiment,which overcomes, at least to some extent, the problems aforesaid, or atleast to provide the public with a useful choice.

SUMMARY OF THE INVENTION

In a first aspect the present invention provides a process for producinga dairy product comprising the steps:

-   (a) mixing together MPC and/or whey protein adjusted MPC with fat to    form a paste of protein particles coated in fat, the MPC and/or whey    protein adjusted MPC containing at least 60% protein on a    solids-non-fat (SNF) basis;-   (b) hydrating and acidifying the paste to form a mixture with a pH    of between about 4.5 and 6.0; and-   (c) heating and mixing said mixture until a homogeneous mass forms,    to produce a final dairy product having a protein:water ratio of    between 0.6 and 3.0.

The protein:water ratio of final dairy product is preferably between0.75 and 3.0, more preferably between 1.0 and 3.0 and most preferablybetween 1.5 and 3.0.

Salt (NaCl) may be mixed in with the ingredients at any one or more ofsteps (a), (b) and (c).

The MPC and/or whey protein adjusted MPC and fat, and optionally salt,may be mixed in step (a) at a temperature of between 0 and 60° C.,preferably at a temperature between 35 and 55° C.

The MPC and/or whey protein adjusted MPC is preferably dried and mostpreferably in the form of a powder. The dried MPC and/or whey proteinadjusted MPC may have a protein content of at least 60-70% on a SNFbasis, and preferably has a protein content of at least 85% on a SNFbasis.

The fat may be sourced from any product which includes a high level offat (i.e >60%) such as high fat cream, milk fat, anhydrous milk fat,butter, oils such as vegetable oils, or any other edible fat, and maycomprise a combination of such fats.

In step (b) the paste may be hydrated by the addition of water andacidified by the addition of a food grade acid such as citric acid,lactic acid, hydrochloric acid, sulphuric acid etc.

In step (c) the acidified mixture may be heated to a temperature ofbetween 75 and 95° C., and more preferably between 80 and 90° C. andmixed at low shear (eg between 50-250 rpm).

Once the homogeneous mass has been formed, the mixture may be cooleddirectly or may be placed in a mould before being allowed to cool.

Preferably the dairy product is a cheese or cheese-like product selectedfrom the group comprising cheddar, cheddar-like cheese, parmesan,parmesan-like cheese, gouda, gouda-like cheese, edam, edam-like cheeseand any other hard cheese in a solid block or crumble form.

Depending on the desired composition of the dairy product, the processmay preferably include the step of adding cream powder and/or furtherMPC (including whey protein adjusted MPC and fat adjusted MPC) during orafter step c).

In a second aspect the present invention provides a dairy-based foodproduct produced by a method of the invention. Preferably said dairyproduct is a cheese selected from cheddar, cheddar-like cheese, gouda,gouda-like cheese, edam, edam-like cheese, parmesan, parmesan-likecheese and any other hard cheese in block or crumble form.

DESCRIPTION OF THE FIGURES

A preferred embodiment of the invention will now be described, by way ofexample only, with reference to the accompanying drawing in which:

FIG. 1 is a schematic diagram generally illustrating the process of theinvention.

DETAILED DESCRIPTION

The present invention provides an alternative process of making a cheesehaving a higher total solids composition than can be achieved from knownrecombined cheese processing methods. In particular, the process of thepresent invention allows the ingredients to be combined more easily andhave a greater processability than the same ingredients when used inprior art processes. Further, the process of the invention is flexiblein that the process can be modified in a number of ways to modify thecharacteristics of the final cheese product. The cheeses made by theprocess of the present invention can also form stable functionalingredients for further processing.

In a first embodiment, the present invention provides a process forproducing a dairy product comprising the steps

-   (a) mixing together MPC and/or whey protein adjusted MPC with fat to    form a paste of protein particles coated in fat, the MPC and/or whey    protein adjusted MPC containing at least 60% protein on a    solids-non-fat (SNF) basis;-   (b) hydrating and acidifying the paste to form a mixture with a pH    of between about 4.5 and 6.0; and-   (c) heating and mixing said mixture until a homogeneous mass forms,    to produce a dairy product having a protein:water ratio of between    0.6 and 3.0.

The general steps of this process are set out in FIG. 1.

The dairy product made by this process may comprise a hard or extra hardcheese including cheddar, cheddar-like cheese, gouda, gouda-like cheese,edam, edam-like cheese, parmesan, parmesan-like cheese and any otherhard cheese in block or crumble form.

The starting milk protein concentrate (MPC) may be produced from milksourced from any milk producing animal by methods known in the art orpurchased from a commercial source such as from New Zealand MilkProducts Ltd.

By MPC is meant a milk protein product in which the milk protein contentof the dry matter is above that typically found in milk and the ratio ofcasein to whey proteins is approximately that of milk. Preferably themilk protein content of the MPC is at least 60%, and more preferably 70%or more, of the solids-non-fat (SNF) dry matter. Such concentrates areknown in the art. Dried MPC can be formed by evaporating or drying MPCby techniques known in the art.

“Whey protein adjusted MPC” as used herein means an MPC which has beenadjusted in whey protein content either by increasing the whey proteincontent by adding whey protein from a dairy stream such as whey proteinconcentrate or permeate from microfiltered skid milk, for example, or bydepleting the whey protein content by microfiltration, for example.

“Fat adjusted MPC” as used herein means an MPC which has been adjustedin fat content either by increasing the fat content by adding fat suchas cream, for example, or by depleting fat by known methods.

The fat may be sourced from any product which includes a high level offat (i.e >60%) such as high fat cream, milk fat, anhydrous milk fat,butter, oils such as vegetable oils, or any other edible fat, and maycomprise a combination of such fats.

The preferred embodiment of the invention involves a three step processas set out above. Step (a) involves mixing MPC powder and fat at atemperature sufficient to melt the fat and form a paste of powderparticles coated with liquefied fat. The MPC powder contains preferably70% or more protein on an SNF basis and is selected from the groupcomprising standard, ion-exchanged MPC, mineral-adjusted MPC, wheyprotein or fat adjusted MPC or a combination of one or more such MPCs.The fat source, which is preferably anhydrous milk fat, can optionallybe flavoured and/or coloured. Salt (NaCl), emulsifying salts (e.g.disodium phosphate), flavours and colours are optionally added to themixture in this first step. The paste of powder particles coated withliquefied fat is formed by mixing the mixture at low shear (eg 50-250rpm in a blentech cooker) at up to 60° C. (preferably 40-50° C. whenmilk fat is used) for at least one minute, preferably two minutes. Asmentioned above, the temperature of mixing needs to be sufficiently highto ensure that the fat is molten, so that it can coat the protein with asufficient covering of fat to control subsequent hydration of the MPCpowder—fat mixture whilst maintaining the processability of the mixtureby avoiding degrees of viscosity which would be too high to work with.As different fat sources have different melting points, the temperaturesat which the ingredients of step (a) are mixed will vary depending onthe fat source as will be appreciated by a skilled person. For oils, themixing of MPC and fat may occur at room temperature or below. For milkfat, a temperature of about 40° C. is preferred.

Preferably the amount of fat added during the step (b) is calculated toconstitute less than 35%, more preferably less than 25% of the finaldairy product. With higher fat levels problems such as poor fatincorporation and fat destabilisation can occur which may lead to theformation of a greasy product.

If the temperature during the formation of the paste is too high,destabilization of the protein/fat matrix during the subsequentheating/low shear mixing stage may result. Because of this it has beenfound desirable to keep the temperature of the initial mixing of thedried MPC and milk fat at step (a) to 60° C. or below.

Without being bound by theory, the inventors believe that the process ofthe present invention achieves a high protein:water ratio in the finaldairy product by controlling the rate and extent of hydration of theprotein so that enough water is added to develop the desired texture andstructure for the final dairy product, without destabilising the fat.Such controlled hydration appears to avoid the exponential increase inviscosity observed when reconstituting milk protein powders to highsolids concentration in prior art processes.

Step (b) involves hydrating and acidifying the paste of powder particlescoated with liquefied fat. This involves the addition of acid and waterto adjust the pH to 4.5 to 6.0. For a hard or extra hard cheese block,the pH should be adjusted to give a final pH of 5.2-5.6. For a “crumble”product i.e. a solid cheese mass which easily disintegrates uponapplication of force, the pH should be adjusted to approximately4.6-4.8, with the later addition of further MPC powder, preferably afterstep (c), to bring the pH back up into the range 5.2-5.6. Those skilledin the art will appreciate that it is the final pH of the product thatis important for product characteristics, such as flavour ormicrobiological stability.

The hydration needs to be sufficient to provide enough moisture for acheese or cheese-like product to form. However it should not be so muchas to lead to the formation of viscosities that are too high to bepractical to work with. The degree of hydration should therefore becontrolled such that a stable dairy product can result, i.e. a productwhere the fat is dispersed and entrapped within the protein matrix,while maintaining the processability of the mixture.

For pH adjustment, any food grade, organic or inorganic acid can be usedsuch as lactic acid, citric acid, hydrochloric acid, sulphuric acid etc.Salt, flavour or colours are optionally added at this step.

In step (c) the mixture is heated to a temperature of between 75-85° C.,preferably by direct steam injection and mixing conducted at low shearfor between one and ten minutes, preferably between two and five minutesuntil a homogeneous mass forms with no free fat and no lumps ofundissolved powder. The protein:water ratio of the dairy product istypically between 0.6 and 3.0, preferably between 0.75 and 3.0, morepreferably between 1.0 and 3.0 and most preferably between 1.5 and 3.0.

It is also been found that during step (c) it is desirable to have atemperature of between 75° C. and 95° C. to ensure all of the fat isincorporated into the protein matrix and to avoid fat destabilisation.

Further, it is desirable that the heating/low shear mixing at step (c)is conducted for between one and ten minutes, as when the mixture ismixed for more than ten minutes the mix can develop extremely highviscosity, which is unmanageable and there is also the potential for fatdestabilization.

Further MPC powder, fillers (such as vegetable protein, starch,maltodextrin, or rice flour), flavours and seasonings, additional saltand acid is optionally added after step (c) to further modify flavourand texture or further increase the solids content of the dairy product.Fat adjusted MPC or cream powder can also be added if desired. If suchadditional ingredients are used, further mixing is conducted atapproximately 75 to 85° C. (without the need for any additional heating)for one minute or more, preferably two minutes to blend addedingredients. To achieve a dairy product having a high protein:waterratio such additional ingredients may be required.

Other GRAS (Generally Regarded As Safe) ingredients common to cheesemaking processes, may be added at any step in the process to alter anyfunctional characteristic or to improve flavour, texture, colour and thelike, as would be understood by a person of skill in the art.

GRAS ingredients include non-dairy ingredients such as stabilisers,emulsifiers, natural or artificial flavours, colours, starches, water,gums, lipases, proteases, mineral and organic acid, structural protein(soy protein or wheat protein), and anti microbial agents as well asdairy ingredients which may enhance flavour and change the protein tofat ratio of the final cheese. In particular, flavour ingredients maycomprise various fermentation and/or enzyme derived products or agedcheese or mixtures thereof as would be appreciated by a skilled worker.The flexibility of allowing any combination of additives to be added atany step in the process allow the final composition of the cheese to beprecisely controlled, including the functionality characteristics.

All of the mixing described in the present invention is preferablyconducted at low shear, e.g. 50-250 rpm in a blentech cooker. However,mixing could also be conducted at high shear, eg 1500-3000 rpm in astephan cooker.

Once the homogeneous mass has been formed, it is allowed to cool to formthe dairy product, the mass may be shaped or pressed in a mould beforecooling.

Where the dairy product is a hard cheese or extra hard cheese in blockform, such a hard block may be further processed, e.g., shredded, orgrated, milled and dried. Free flow agents (e.g., silica), anti-mycoticagents (e.g. potassium sorbate) and flavours (e.g. seasonings) can beadded to the shredded or grated/milled cheese product to improve flowcharacteristics and shelf stability. If the homogeneous mass is simplyallowed to cool without moulding or further processing a dairy-based“crumble” will form. In a preferred embodiment the crumble has amoisture range of 15-25%. The crumble can be further processed orgrated/milled.

The process of the preferred embodiment uses conventional foodprocessing equipment, such as processed cheese equipment, and the unitoperations are standard as would be understood by a person skilled inthe art.

It is anticipated that ion-exchange, mineral-adjusted, whey protein orfat adjusted MPCs can be used to optimize the dairy products produced bythe process of the invention and to manipulate the specific texturalcharacteristics of the dairy products. Emulsifying salts and other GRASingredients can also be used to manipulate the textural characteristicsof the dairy product as would be understood by a skilled person.

In particular, emulsifying salts such as disodium phosphate,polyphosphate, or citrate are all suitable for use in the invention.Typically, salt and emulsifying salts are added as part of the initialpowder mix in step (a).

Dried MPC is commercially available in a number of forms. MPC56, MPC70and MPC85 are three such common forms available from new Zealand MilkProducts Ltd., the “56”, “70” and “85” referring to the present proteinfound in these powders. It is anticipated that any combination of MPCtypes to give a percent protein of at least 60% and preferably 70% ormore will work in the invention, for example a 50:50 mixture of MPC70and MPC85. Similarly any combination of fat, fillers, flavouringredients, seasonings, acids, salts and emulsifying salts and otherGRAS ingredients can be used depending on the desired characteristics ofthe dairy product.

The present invention also provides a alternative manufacturing processfor the production of grated/dried Parmesan style cheese. This advantageis derived from the elimination (or at least uncoupling) of the dryingstep that is required with the traditional manufacture of Parmesancheese.

A significant advantage of the process of the present invention overtraditional cheese making processes is that the product is formedwithout the need for maturation, although the product can be aged ifdesired.

The present invention can be used to produce dairy products other thancheese or cheese-like products. For example, by adding various flavoursor emulsifiers to the process of the invention, dairy products can beformed that have quite different taste and texture to traditionalcheeses. For example the present invention could be used to make apeppermint, tomato, strawberry, etc flavoured gel/crumble product.

In a further embodiment, the present invention provides a hard or extrahard cheese product produced by the process of the invention.

The present invention also provides a food product comprising the cheeseof the present invention.

Any ranges mentioned in this patent specification are intended toinherently include all of the possible values within the stated ranges.

This invention may also be said broadly to consist in the parts,elements and features referred to or indicated in the specification ofthe application, individually or collectively, and any or allcombinations of any two or more of said parts, elements or features, andwhere specific integers are mentioned herein which have knownequivalents in the art to which this invention relates, such knownequivalents are deemed to be incorporated herein as if individually setforth.

The present invention will now be exemplified.

EXAMPLE 1

1319 g of anhydrous milk fat was placed into a twin screw process cheesecooker with a capacity of 5 kg (Blentech Corporation, Rohnert Park,Calif.) that had been pre-heated to 100° C. This was blended for 1minute with the rotational speed of the twin screws set at ˜170 rpm.1436 g of MPC 70 (marketed as ALAPRO® 4700 by NZMP Ltd), and 72 g ofNaCl were added to the cooker and blended for 1.5 minutes. At this pointthe blend had reached 50° C. 1293 g of cold water and 50 g of 80% lacticacid were added and mixed with culinary steam until the temperaturereached 85° C. After the steam was turned off, the product was mixed for2 minutes. The hot product was thick and creamy and well blended, withno free fat. It pumped easily out of the cooker into moulds and waschilled to set. The final product had a firm, cheese-like texture,similar to Cheddar cheese. The protein to water ratio was 0.6, moisturecontent 38%, pH 5.46 and fat content about 30%.

EXAMPLE 2

1328 g of anhydrous milk fat was placed into a twin screw process cheesecooker with a capacity of 5 kg (Blentech Corporation, Rohnert Park,Calif.) that had been pre-heated to 100° C. This was blended for 1minute at ˜170 rpm. 1296 g of MPC 85 (marketed as ALAPRO® 4850 by NZMPLtd), 247 g of sweet whey powder (marketed as ALAWAY® 621 by NZMP Ltd),75 g of disodium phosphate and 72 g of NaCl were added to the cooker andblended for 6 minutes. At this point the mixture had reached 50° C. 1070g of cold water mixed with 81 g of 80% lactic acid were added and mixedwith culinary steam until the temperature reached 85° C. After the steamwas turned off, the product was mixed for 2 minutes. The hot product wasthick, smooth and well blended, with no free fat. It pumped easily outof the cooker into moulds, and was chilled to set. The final product hada firm, cheese-like texture, similar to Parmesan cheese. The protein towater ratio was 0.7, moisture content 35.4%, pH 5.38 and fat contentabout 30%.

EXAMPLE 3

Into a twin screw process cheese cooker with a capacity of 5 kg(Blentech Corporation, Rohnert Park) that had been preheated to 100° C.was placed 1328 g of anhydrous milk fat, 1,636 g of MPC 70 (marketed asALAPRO® 4700 by NZMP Ltd), and 72 g NaCl. The ingredients were thenmixed for 3 minutes at ˜170 rpm. At this point the blend temperature was50° C. 1067 g of cold water and 68 g of 88% lactic acid were added andmixed with culinary steam until the temperature reached 85° C. Themixture was then cooked for 2 minutes. An homogeneous mass formed andwas easily pumped out of the cooker and cooled in moulds. The finalblock was firm and had a cheese-like texture, similar to Cheddar cheese.The pH of the final product was 5.5, moisture content 33.7%, protein 25%and fat 20%. The protein to water ratio was 0.8

EXAMPLE 4

873 g of anhydrous milk fat was placed into a twin screw process cheesecooker with a capacity of 5 kg (Blentech Corporation, Rohnert Park,Calif.) that had been pre-heated to 100° C. This was blended for 1minute at ˜170 rpm. 2093 g of MPC 70 (marketed as ALAPRO® 4700 by NZMPLtd) and 72 g of NaCl were added to the cooker and blended for 1.5minutes. At this point the blend temperature was 50° C. 1047 g of coldwater and 86 g of 88% lactic acid were added and mixed with culinarysteam until the temperature reached 85° C. After the steam was turnedoff, the product was mixed for 2 minutes. The hot mass was uniformlyblended, slightly spongy, with no free fat. It was pumped out of thecooker into block moulds, then chilled. The final product had a firm,cheese-like texture, similar to Cheddar cheese. The protein to waterratio was 1.0, moisture content 32.2%, pH 5.42 and fat content of 20%.

EXAMPLE 5

1,187 g of anhydrous milk fat, 2,040 g MPC 85 (marketed as ALAPRO 4850by NZMP Ltd), 95 g NaCl and 104 g disodium phosphate were mixed at lowshear in a twin screw process cheese cooker with a capacity of 5 kg(Blentech Corporation, Rohnert Park, Calif.) and heated to 35° C. byindirect steam. The mixture was blended for 2 minutes at ˜170 rpm. 1,052g of water and 52 g of citric acid were added and mixed at low shearwith direct steam addition until the temperature of the mixture reached85° C. This took 5 minutes and 38 seconds. The steam was turned off andlow shear mixing continued. The temperature peaked at 88.6° C. 50 g ofdried Romano flavour was added over a period of 20-30 seconds, while lowshear mixing continued. After 12 minutes of mixing a smooth emulsionhomogeneous mass formed. The emulsion was cooled at ambient temperature.The product has a firm, cheese-like texture., similar to Parmesancheese. The final pH of the product was 5.4. The protein to water ratiowas 1.2 and the fat content was 25%.

EXAMPLE 6

1,958 g of MPC 56 (marketed as ALAPRO® 4560 by NZMP Ltd), 869 ganhydrous milk fat, and 72 g of NaCl were placed into a twin screwprocess cheese cooker with a capacity of 5 kg (Blentech Corporation,Rohnert Park, Calif.) that had been pre-heated to 100° C. Theseingredients were then mixed for 3 minutes at ˜170 rpm. At this point theblend had reached 57° C. 621 g of cold water and 120 g of 88% lacticacid were added and mixed with culinary steam until the temperaturereached 85° C. The mixture was then cooked for 2 minutes. Another 658 gof MPC 56 was added and mixed for 2 minutes. A homogeneous mass formed,discharged onto a tray, and cooled quickly in a freezer (−18° C.). Whencooled, the product was milled using an Urschel Commitrol mill with120th of an inch cutting head. After milling, fine granules, similar todried, grated cheese, were formed. The pH of the end product was 5.2,the protein to water ratio was 1.6, fat content was 30% and the moisturecontent 20.7%.

EXAMPLE 7

Into a twin screw process cheese cooker with a capacity of 5 kg(Blentech Corporation, Rohnert Park, Calif.), pre-heated to 100° C. wasplaced 873 g of anhydrous milk fat, 1607 g of MPC 70 (marketed asALAPRO® 4700 by NZMP Ltd) and 72g of NaCl. The ingredients were blendedfor 3 minutes at ˜170 rpm. At this point the blend temperature was 47°C. 626 g of cold water and 120 g of 88% lactic acid were added and mixedwith culinary steam until the temperature reached 85° C. After the steamwas turned off; the product was mixed for 2 minutes. 386 g more MPC 70and 635 g of cream powder (marketed as ALACO Cream Powder 70 by NZMPLtd) was added to the blend and mixed for 2 minutes. The hot product waseasily pumped out of the cooker onto a tray, spread out evenly and thenchilled rapidly in a freezer (−18° C.). When cooled, the product wasmilled using an Urschel Commitrol mill with 120th of an inch cuttinghead. After milling, fine granules, similar to dried, grated cheese,were formed. The protein to water ratio was 1.6, with 21.3% moisture,30.2% fat, 32% protein and a pH of 5.1.

EXAMPLE 8

869 g of anhydrous milk fat was placed into a twin screw process cheesecooker with a capacity of 5 kg (Blentech Corporation, Rohnert Park,Calif.) that had been pre-heated to 100° C. This was blended for 1minute at ˜170 rpm. 1476 g of MPC 70 (marketed as ALAPRO® 4700 by NZMPLtd), and 72 g of NaCl were added to the cooker and blended for 2minutes. At this point the blend temperature was 53° C. 554 g of coldwater and 120 g of 88% lactic acid were added and mixed with culinarysteam until the temperature reached 85° C. After the steam was turnedoff, the product was mixed for 2 minutes. 604 g of MPC 70 and 604 g ofMaize Cornflour were added to the cooker and mixed for 2 minutes. Ahomogeneous mass formed and was cooled quickly on a tray in a freezer(−18° C.). When cooled, the product was milled using an UrschelCommitrol mill with 120th of an inch cutting head. After milling, finegranules, similar to dried, grated cheese, were formed. The protein towater ratio was 1.6, with 20.2% moisture, 19.9% fat, 32.9% protein and apH of 5.22.

EXAMPLE 9

1,605 g of MPC 70 (marketed as ALAPRO® 4705 by NZMP Ltd), 933 ganhydrous milk fat and 74 g of NaCl were placed in a a twin screwprocess cheese cooker with a capacity of 5 kg (Blentech Corporation,Rohnert Park, Calif.) that had been pre-heated to 100° C., and mixed for2 minutes at ˜170 rpm. 505 g of water and 120 g of 88% lactic acid wereadded and mixed with direct steam until the temperature reached 85° C.The mixture was then mixed for 4 minutes. 1,016 g more MPC 70 were addedand again mixed at low shear for 1 minute. A homogeneous mass formedwhich was emptied onto a tray and cooled rapidly. A crumble with novisible fat resulted that could easily be ground to become similar tograted, dried cheese. The pH of the final product was 5.6, fat contentwas 20%, and moisture content 21.5%. The protein to water ratio wasabout 1.9.

EXAMPLE 10

A twin screw process cheese cooker with a capacity of 5 kg (BlentechCorporation, Rohnert Park, Calif.) was preheated to 100° C. with steam.1553 g of MPC 70 (marketed as ALAPRO® 4700 by NZMP Ltd), 72 g of NaCland 1130 g of high solids cream (78% solids) were put into the cooker,then mixed for 1 minute at ˜170 rpm. At this point the blend had reached53° C. 360 g of water with 120 g of 88% lactic acid mixed into it wasadded to the cooker and mixed with addition of culinary steam to heatthe contents to 85° C. The heated mass was mixed for 2 minutes. 1063 gmore MPC 70 was added and mixed for 2 minutes. The final product formedfine granules, similar to grated, dried cheese. It had a final moisturecontent of 20.0%, 19.7% fat, 41.0% protein, 6.1% ash and pH of 5.3. Theprotein to water ratio was 2.1.

EXAMPLE 11

A twin screw process cheese cooker with a capacity of 5 kg (BlentechCorporation, Rohnert Park, Calif.) was preheated to 100° C. with steam.1605 g of MPC 70 (marketed as ALAPRO® 4705 by NZMP Ltd), 74 g of NaCland 933 g of anhydrous milk fat were put into the cooker, then mixed for2 minutes at ˜˜170 rpm. At this point the blend had reached 53° C. 305 gof water with 60 g of citric acid powder dissolved into it was added tothe cooker and mixed with addition of culinary steam to heat thecontents to 88° C. The heated mass was mixed for 2 minutes. 1016 g moreMPC 70 was added and mixed for 1 minute. The final product formed finegranules, similar to grated, dried cheese. It had a final moisturecontent of 14.7%, 24.5% fat and pH of 5.89. The protein to water ratiowas about 2.9.

The following two examples are comparative examples carried out inaccordance with prior art methods where all ingredients were simplymixed together without first forming a paste of protein powder and fat.

COMPARATIVE EXAMPLE 1

A twin screw process cheese cooker with a capacity of 5 kg (BlentechCorporation, Rohnert Park, Calif.) was preheated to 100° C. 2477 g ofMPC 70 (marketed as ALAPRO® 4700 by NZMP Ltd), 1187 g anhydrous milkfat, 95 g salt, 52 g citric acid and 1052 g water were added to thecooker, then mixed. Steam was turned on and the mixture heated to 85° C.The product was then mixed for 15 minutes (at ˜170 rpm) with regularchecking to see if the fat had been incorporated. At no point in the15-minute period was the fat incorporated, and hence no emulsion wasformed. The protein formed nuggets about 1-2 cm in diameter, with a poolof fat around and coating them. The final dairy product did not resemblea cheese-like product.

COMPARATIVE EXAMPLE 2

A twin screw process cheese cooker with a capacity of 5 kg (BlentechCorporation, Rohnert Park, Calif.) was preheated to 100° C. 2477 g ofMPC 70 (marketed as ALAPRO® 4700 by NZMP Ltd), 1187 g anhydrous milkfat, 95 g salt, 104 g disodium phosphate 52 g citric acid and 1052 gwater were added to the cooker, then mixed at ˜170 rpm. Steam was turnedon and the mixture heated to 85° C. with mixing. The product was thenmixed for a further 15 minutes, with regular checking, to see if the fathad been incorporated. At no point in the 15-minute period was the fatincorporated. The product was a very viscous mass of hydrated proteinstuck to the augers with lots of free fat on the surface and poolingaround it. The final product did not resemble a cheese-like product.

INDUSTRIAL APPLICATION

The process of the present invention provides dairy products and moreparticularly cheese products having a high protein to water ratio in arelatively simple and fast process using conventional cheese makingapparatus.

Although the invention has been described with reference to specificexamples, it will be appreciated by those skilled in the art that it isnot intended to limit the invention to the above examples only, manyvariations being possible without departing from the scope of theinvention as defined in the accompanying claims.

1. A process for producing a dairy product comprising the steps: (a)mixing together MPC and/or whey protein adjusted MPC with fat to form apaste of protein particles coated in fat, the MPC and/or whey proteinadjusted MPC containing at least 60% protein on a solids-non-fat (SNF)basis; (b) hydrating and acidifying the paste to form a mixture with apH of between about 4.5 and 6.0; and (c) heating and mixing said mixtureuntil a homogeneous mass forms, to produce a dairy product having aprotein:water ratio of between 0.6 and 3.0.
 2. A process as claimed inclaim 1, wherein the protein:water ratio of the dairy product is between0.75 and 3.0.
 3. A process as claimed in claim 2, wherein theprotein:water ratio of the final dairy product is between 1.0 and 3.0.4. A process as claimed in claim 3, wherein the protein:water ratio ofthe dairy product is between 1.5 and 3.0.
 5. A process as claimed inclaim 1, wherein salt (NaCl) is mixed in with the ingredients at any oneor more of steps (a) and (c).
 6. A process as claimed in claim 1,wherein the MPC and/or whey protein adjusted MPC and fat are mixed instep (a) at a temperature of between 0 and 60° C.
 7. A process asclaimed in claim 6, wherein MPC and fat are mixed in step (a) at atemperature of between 35 and 55° C.
 8. A process as claimed in claim 1,wherein the MPC and/or whey protein adjusted MPC is dried and in theform of a powder.
 9. A process as claimed in claim 8, wherein the driedMPC and/or whey protein adjusted MPC has a protein content of at least70% on a SNF basis.
 10. A process as claimed in claim 9, wherein thedried MPC has a protein content of at least 85% on a SNF basis.
 11. Aprocess as claimed in claim 1, wherein the fat comprises a fat selectedfrom the group consisting of high fat cream, milk fat, anhydrous milkfat, butter, oil, vegetable oil, and any other edible fat.
 12. A processas claimed in claim 1 or 11, wherein the amount of fat added in step (a)is calculated to constitute less than 35% of the dairy product.
 13. Aprocess as claimed in claim 1, wherein in step (b) the paste is hydratedby the addition of water and acidified by the addition of one or moresuitable food grade acids.
 14. A process as claimed in claim 1 or 13,wherein the mixture of step (b) is acidified to a pH of between 5.2 and5.6.
 15. A process as claimed in claim 1, wherein in step (c) theacidified mixture is heated to a temperature of between 75 and 95° C.and mixed at low shear.
 16. A process as claimed in claim 15, whereinthe mixture at step (c) is heated to 80-90° C.
 17. A process as claimedin claim 1 wherein one or more GRAS ingredients are added at one or moreof steps (a) to (c).
 18. A process as claimed in claim 17, wherein saidGRAS ingredients are selected from the group consisting of non-dairystabilizers, emulsifiers, natural or artificial flavors, seasonings,salt, colors, starches, maltodextrin, rice flour, water, gums, lipases,proteases, mineral and organic acids, structural protein (soy protein orwheat protein), anti microbial agents non-dairy fat, dairy flavorsincluding fermentation and enzyme derived products or aged cheese ormixtures thereof, dairy fat, cream powder, MPC and dairy proteincontaining ingredients.
 19. A process as claimed in claim 1 furthercomprising step (d) wherein additional MPC, protein adjusted MPC, fatadjusted MPC, one or more fillers and/or cream powder is added to themixture after step (c) and additional mixing carried out at 75-85° C.for at least one minute to increase the solids content of the dairyproduct.
 20. A process as claimed in claim 1 wherein once thehomogeneous mass has been formed, the mixture is cooled directly orplaced in a mold before being allowed to cool to form a dairy product.21. A process as claimed in claim 1 where the dairy product is a cheeseor cheese-like product selected from the group consisting of cheddar,cheddar-like cheese, parmesan, parmesan-like cheese, edam, edam-likecheese and any other hard cheese in a solid block or crumble form.